1. Field of the Invention
The present invention relates to a communication conditions determination method of determining the communication conditions of a first communication network and a second communication network which are connected by a connection apparatus such as a router, a communication conditions determination system that employs the communication conditions determination method, and a determination apparatus used in the communication conditions determination system. In particular, the present invention relates to a communication conditions determination method, a communication conditions determination system, and a determination apparatus, in which a communication network whose communication conditions are poor is identified.
2. Description of the Related Art
One of the tasks performed by an entity, such as an ISP (Internet Service Provider), that provides services allowing users to use the Internet includes, upon occurrence of a communication failure such as a packet loss or a delay caused by a congestion on a communication network, an identification of the failure point and a support for the failure. Services provided by an entity such as an ISP use a plurality of communication networks including a customer network, a carrier network, and an ISP network whose administrators are different from one another. When a communication failure occurs, it is necessary to identify, among the customer, carrier, and ISP networks, a communication network on which the communication failure is occurring.
Japanese Patent Application Laid-Open No. 2002-077160 discloses a method in which a measurement apparatus that extracts packet data is disposed at a plurality of points on a communication network, packet data obtained when a single packet passes through each of the points is extracted, and the timestamps of the extracted packet data are compared, whereby communication quality such as a delay time between the extraction points is evaluated. There exists a method of identifying a failure point based on evaluation results.
In addition, Japanese Patent Application Laid-Open No. 2004-104540 discloses a method in which a measurement IP (Internet Protocol) packet is sent to an apparatus on a communication network from a monitoring apparatus and a failure point is identified based on a response time to the sent IP packet.
However, when the method described in Japanese Patent Application Laid-Open No. 2002-077160 is used to identify a communication network on which a communication failure has occurred, a measurement apparatus that extracts packet data needs to be disposed at locations where the communication networks are connected. Since the disposition of the measurement apparatus on a communication network administered by other entities causes various problems, implementation is less feasible.
On the other hand, in the method described in Japanese Patent Application Laid-Open No. 2004-104540, in order to increase the accuracy of measurement, large numbers of IP packets need to be sent. As a result, the traffic is increased, which may adversely affect other communication.